diff --git a/crates/render/src/encode/quantize.rs b/crates/render/src/encode/quantize.rs
index 9c5061f1d..5b3a08b29 100644
--- a/crates/render/src/encode/quantize.rs
+++ b/crates/render/src/encode/quantize.rs
@@ -197,7 +197,8 @@ pub fn quantize_locked(rgba: &[u8], width: u32, height: u32, o: &PaletteOptions,
     }
     let weights = o.reduction.weights();
     let dither = if exact { Dither::None } else { o.dither };
-    let mut indices = map(&colors, width as usize, &palette, weights, dither, f32::from(o.dither_amount.min(100)) / 100.0, |i| clear(&px[i]));
+    // (A width past the pixels there are would size the error rows from a number nothing checked.)
+    let mut indices = map(&colors, (width as usize).min(colors.len()), &palette, weights, dither, f32::from(o.dither_amount.min(100)) / 100.0, |i| clear(&px[i]));
     // Drop the entries no pixel uses (fixed palettes), keeping the order.
     let mut used = [false; 256];
     for (i, &ix) in indices.iter().enumerate() {
diff --git a/crates/render/src/encode/tga.rs b/crates/render/src/encode/tga.rs
index 884276eec..abac01dba 100644
--- a/crates/render/src/encode/tga.rs
+++ b/crates/render/src/encode/tga.rs
@@ -34,11 +34,11 @@ pub fn encode(rgba: &[u8], width: u32, height: u32, o: &TgaOptions) -> Result<Ve
         return Err(format!("{width} × {height} pixels is too large for Targa (at most 65535 pixels a side): lower the resolution"));
     };
     let (w, h) = (usize::from(w16), usize::from(h16));
-    if w == 0 || h == 0 || w * h * 4 != rgba.len() {
+    if w == 0 || h == 0 || (w * h).checked_mul(4) != Some(rgba.len()) {
         return Err("Targa encoding failed: the pixel buffer doesn't match the image size".into());
     }
     let px = rgba.as_chunks::<4>().0;
-    let mut out = Vec::with_capacity(18 + w * h * usize::from(o.depth / 8) + 26);
+    let mut out = Vec::with_capacity((w * h).saturating_mul(usize::from(o.depth / 8)).saturating_add(18 + 26));
     // No image id or colour map, uncompressed true colour, origin (0, 0).
     out.extend([0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0]);
     out.extend(w16.to_le_bytes());